During the framing phase of construction, exterior walls are built over a flat surface such as the first story floor or concrete slab, then raised and braced in the upright position. Exterior wall sheathing may be applied before or after raising the wall. Similarly, completely or partially prefabricated walls may be set and braced in the upright position, prior to framing of the roof. Roof framing can be by trusses or “stick framing” which includes setting the rafters. Typically workers perform much of the roof framing work (fastening the trusses/rafters to the top plates of the wall and installation of blocking between the trusses/ rafters) while standing on the top plate. This exposes the worker to a fall hazard to both the inside and outside of the wall.
Roof-mounted lifeline fall protection systems do not provide adequate structural strength until after the roof understructure has been cross-braced and sheathed. Other possible fall protection systems, such as masonry scaffold or exterior wall-supported scaffold, can be costly and time consuming to set up.